Oidc = {};

OAuth.registerService('oidc', 2, null, function(query) {
  var debug = process.env.DEBUG || false;
  var token = getToken(query);
  if (debug) console.log('XXX: register token:', token);

  var accessToken = token.access_token || token.id_token;
  var expiresAt = +new Date() + 1000 * parseInt(token.expires_in, 10);

  var userinfo = getUserInfo(accessToken);
  if (debug) console.log('XXX: userinfo:', userinfo);

  var serviceData = {};
  serviceData.id = userinfo[process.env.OAUTH2_ID_MAP]; // || userinfo["id"];
  serviceData.username = userinfo[process.env.OAUTH2_USERNAME_MAP]; // || userinfo["uid"];
  serviceData.fullname = userinfo[process.env.OAUTH2_FULLNAME_MAP]; // || userinfo["displayName"];
  serviceData.accessToken = accessToken;
  serviceData.expiresAt = expiresAt;
  serviceData.email = userinfo[process.env.OAUTH2_EMAIL_MAP]; // || userinfo["email"];

  if (accessToken) {
    var tokenContent = getTokenContent(accessToken);
    var fields = _.pick(
      tokenContent,
      getConfiguration().idTokenWhitelistFields,
    );
    _.extend(serviceData, fields);
  }

  if (token.refresh_token) serviceData.refreshToken = token.refresh_token;
  if (debug) console.log('XXX: serviceData:', serviceData);

  var profile = {};
  profile.name = userinfo[process.env.OAUTH2_FULLNAME_MAP]; // || userinfo["displayName"];
  profile.email = userinfo[process.env.OAUTH2_EMAIL_MAP]; // || userinfo["email"];
  if (debug) console.log('XXX: profile:', profile);

  return {
    serviceData: serviceData,
    options: { profile: profile },
  };
});

var userAgent = 'Meteor';
if (Meteor.release) {
  userAgent += '/' + Meteor.release;
}

var getToken = function(query) {
  var debug = process.env.DEBUG || false;
  var config = getConfiguration();
  if (config.tokenEndpoint.includes('https://')) {
    var serverTokenEndpoint = config.tokenEndpoint;
  } else {
    var serverTokenEndpoint = config.serverUrl + config.tokenEndpoint;
  }
  var requestPermissions = config.requestPermissions;
  var response;

  try {
    response = HTTP.post(serverTokenEndpoint, {
      headers: {
        Accept: 'application/json',
        'User-Agent': userAgent,
      },
      params: {
        code: query.code,
        client_id: config.clientId,
        client_secret: OAuth.openSecret(config.secret),
        redirect_uri: OAuth._redirectUri('oidc', config),
        grant_type: 'authorization_code',
        scope: requestPermissions,
        state: query.state,
      },
    });
  } catch (err) {
    throw _.extend(
      new Error(
        'Failed to get token from OIDC ' +
          serverTokenEndpoint +
          ': ' +
          err.message,
      ),
      { response: err.response },
    );
  }
  if (response.data.error) {
    // if the http response was a json object with an error attribute
    throw new Error(
      'Failed to complete handshake with OIDC ' +
        serverTokenEndpoint +
        ': ' +
        response.data.error,
    );
  } else {
    if (debug) console.log('XXX: getToken response: ', response.data);
    return response.data;
  }
};

var getUserInfo = function(accessToken) {
  var debug = process.env.DEBUG || false;
  var config = getConfiguration();
  // Some userinfo endpoints use a different base URL than the authorization or token endpoints.
  // This logic allows the end user to override the setting by providing the full URL to userinfo in their config.
  if (config.userinfoEndpoint.includes('https://')) {
    var serverUserinfoEndpoint = config.userinfoEndpoint;
  } else {
    var serverUserinfoEndpoint = config.serverUrl + config.userinfoEndpoint;
  }
  var response;
  try {
    response = HTTP.get(serverUserinfoEndpoint, {
      headers: {
        'User-Agent': userAgent,
        Authorization: 'Bearer ' + accessToken,
      },
    });
  } catch (err) {
    throw _.extend(
      new Error(
        'Failed to fetch userinfo from OIDC ' +
          serverUserinfoEndpoint +
          ': ' +
          err.message,
      ),
      { response: err.response },
    );
  }
  if (debug) console.log('XXX: getUserInfo response: ', response.data);
  return response.data;
};

var getConfiguration = function() {
  var config = ServiceConfiguration.configurations.findOne({ service: 'oidc' });
  if (!config) {
    throw new ServiceConfiguration.ConfigError('Service oidc not configured.');
  }
  return config;
};

var getTokenContent = function(token) {
  var content = null;
  if (token) {
    try {
      var parts = token.split('.');
      var header = JSON.parse(new Buffer(parts[0], 'base64').toString());
      content = JSON.parse(new Buffer(parts[1], 'base64').toString());
      var signature = new Buffer(parts[2], 'base64');
      var signed = parts[0] + '.' + parts[1];
    } catch (err) {
      this.content = {
        exp: 0,
      };
    }
  }
  return content;
};

Oidc.retrieveCredential = function(credentialToken, credentialSecret) {
  return OAuth.retrieveCredential(credentialToken, credentialSecret);
};
